TW200903527A - Laminated positive temperature coefficient thermistor - Google Patents

Abstract

A laminated positive temperature coefficient thermistor is provided with a ceramic element (1) wherein semiconductor ceramic layers (3a-3e), each of which has BaTiO3 as a main component and contains an agent to make material semiconductive, and a plurality of internal electrodes (4a-4d) are alternately laminated, and the outermost layers are formed of semiconductor ceramic layers (3a, 3e). The outermost layers form protection layers (5), and an effective layer (6) is formed by the semiconductor ceramic layers sandwiched between the internal electrodes (4a, 4d). The protection layer (5) contains an agent for making material semiconductive, and the agent has an ion radius larger than that of the agent contained in the effective layer (6), and a hole ratio of the protection layer (5) is lower than that of the effective layer (6).; Preferably, a glass film is formed in the hole on the surface of the protection layer (5) to have the hole ratio of the protection layer (5) 10% of below. Thus, entry of flux into the semiconductor ceramic layer is eliminated without generating delamination, and a desired resistance change rate is ensured.

Description

200903527 IX. Description of the Invention: [Technical Field] The present invention relates to a resistor for overcurrent protection, temperature detection, and the like. Stomach augmentation heat [Prior Art] In recent years, the progress of electronic equipment has been miniaturized, and it has been used for the positive resistance temperature characteristics, and the crying, the s s u , /, and the heat are also progressing. As such a positive thermal resistor of the type, it is known that there is, for example, a laminated positive thermal resistor.曰 - The well-known laminated positive thermal resistance system has Tao Jing body

For example, (10) 复 复 复 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 半导体 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复 复External electrode. Electrode and as the internal electrode of the laminated positive thermal resistor, it is known to use

electrode. Usually, the ceramic matrix of the laminated positive thermal resistance device is made of ceramic green sheets of the L-shaped ceramic layer. (5) The non-embryo (with (10) fine) will be used as the conductive paste for the internal electrodes of the state internal electrodes. Screen printing is carried out, and the ceramic plaque layer printed with the conductive paste for the inner pole is printed, and the internal electrodes of the state are mutually exchanged with the two end faces of the ceramic body, and are applied in a special atmosphere; Boiled to form. At that time, if it is in the atmosphere, the internal electrode of the body will be oxidized. Therefore, a system having a semiconductor (four) layer and an internal electrode is formed by burning in a reducing atmosphere. Huan: 'The right-to-reduction atmosphere is the body-fired', and the semi-conductive ceramic layer is also ',' which creates a new problem that a sufficient rate of change in resistance cannot be obtained. Therefore, the main 129283.doc 200903527 obtains a high-resistance change, an electric-electricity, and a culture rate, which is known to be re-oxidized in an atmosphere or an oxygen atmosphere in a reducing atmosphere. ^ This re-emulsification treatment is difficult to control (4) treatment temperature, and since oxygen does not spread to the center of the element body 33', oxidation unevenness occurs, and a sufficient rate of change in resistance cannot be obtained. For example, Patent Document 1 discloses that the sintering density of the semiconductor ceramic layer is lowered and the ratio of the existence of the voids is increased, whereby the structure in which oxygen easily spreads to the central portion of the ceramic body is obtained.

* When such a positive thermal resistance of high porosity is mounted on a substrate, soldering is usually performed by reflow soldering, but the help contained in the solder (4) is invaded through the pores of the semiconductive ceramic layer located on the surface of the ceramic body. Inside the ceramic body, the withstand voltage may be reduced. As a method for solving the problem, in Patent Document 1, it is known that a ceramic film is impregnated with a glass component to form a glass film in the pores of the semiconductor ceramic layer present on the surface of the ceramic body, thereby preventing the reinforcing agent from being ceramic. Internal invasion of the body. [Patent Document 1] JP-A-2002-217004 SUMMARY OF INVENTION (Problems to be Solved by the Invention) However, even as in the patent document, the pores of the surface of the ceramic body having a low sintered density of the semiconductor ceramic layer are obtained. If there are too many pores in the impregnated glass component, depending on the type of the glass component and the impregnation/drying and burning conditions, the pores may not be sufficiently filled. Therefore, the porosity of the semiconductive ceramic layer located on the surface side of the ceramic body is preferably low. Accordingly, the object of the present invention is to provide a laminated positive thermal resistor which provides a porosity of the semiconductor ceramic layer located at the central portion of the ceramic body at the same level as in Patent 129283.doc 200903527, and is located on the surface of the ceramic body. The porosity of the semiconductor ceramic layer is lower than that of the hole (4) of the semiconductor ceramic layer in the central part of the ceramic body. (Technical means to solve the problem) - In order to achieve the above object, the present invention is revisited and the θt temple is repeatedly reviewed. The result is that I will now exist in the outermost layer of the stacking positive thermistor. The plurality of semiconductor ceramic layers between the two internal electrodes are used as effective sounds, and the two inner electrodes respectively located at the outermost side are located on the surface of the ceramic body.

When the Hi conductor ceramic layer is used as the protective layer, the porosity of the effective layer can be substantially increased by changing the type of the semiconductor ceramic layering agent to which the semiconductor compounding layer of the semiconductor ceramic layer constituting the active layer is formed. The porosity of the protective layer is smaller than the porosity of the active layer. The laminated positive thermal resist body of the first invention of the present invention is composed of a plurality of semiconductor cores, and 3 layers of red and scorpion ceramic layers are laminated with a plurality of internal electrodes. The semiconductor (four) layer includes a ceramic material containing BaTi〇3 as a main component, and the interface of the 辇3 cow lead basket is formed, and the σ electrode is formed along the surface of the semiconductor ceramic layer f; ^ , / , is formed in the outermost direction of the ceramic body (10) 妾; 70%, will be located in the layer as an effective layer, the complex semiconductor ceramic layer exists in the ratio between the two "The two inner electrodes on the outermost side are the semi-conductors on the surface side of the element body." As the protective layer, the radius ratio is the front, and the ion of the body is the former. The ionic radius of the agent is large. Semiconductorization 129283.doc 200903527 and the second aspect of the present invention, the laminated positive thermal resistor is preferably used to protect the pores of the semiconductor layer 1 of b, at least in the ceramic body. The pores on the surface side are formed with a glass film. Further, in the laminated positive thermal resistor of the third invention of the present invention, the porosity of the protective layer is preferably 10% or less. (Effect of the Invention) f According to the first invention of the present invention, a plurality of semiconductor ceramic layers existing between two internal electrodes which are respectively located at the outermost side in the lamination direction of the laminated positive thermal resistor are used as effective layers, and the ratios are respectively located at the most When the two outer electrodes are located on the surface of the surface of the Tauman body as the protective layer, the ion half of the semiconductorizing agent contained in the semiconductor ceramic layer forming the protective layer becomes the effective layer. The composition of the ion of the semiconductorizing agent contained in the semiconductor Tauman layer, and the firing of the effective layer and the protective layer on the surface of the ceramic body, the porosity of the surface portion of the ceramic body, that is, the porosity of the protective layer What?丨 Low gap rate. This is based on the new insights of the Shanghai-Zhenyue 4, that is, the BaTi〇3 series semi-conductor 2: the larger the ionic radius of the semiconductorizing agent contained in the material, the half-conductor Tao Jing obtained by roasting at a specific temperature k The porosity of the layer is smaller. Accordingly, the semiconductor of the semiconductor material contained in the semiconductor material is immersed in the ionization of the semiconductor device. (4) 3 sounds and ❸大' even if the body-fired protective layer and the effective same-path sound layer (4) (4) can be maintained In contrast to the past, the protective layer is used to make the porosity of the layer of reoxidation after the calcination is low. Internal Retoiu - Handling Nisshin, in the central part of the ceramic body and directly contributing to the effective layer of the characteristic, can only be used to maintain the state of oxygen, and 纩f & The small size does not contribute to the characteristics and the flux is easily oozing the porosity of the protective layer 129283.doc 200903527. In the case of the semiconductor ceramic layer, which is designed to change the porosity one by one, for example, Japanese Laid-Open Patent Publication No. 2005-93574, which is a binder contained in a ceramic green sheet which is a semiconductor layer of a fired L, is mixed with polyphenylene. The particles 'change the amount of polystyrene particles to adjust the amount of pores which occur due to combustion and disappearance of the polyphenylene oxide particles after calcination, so that the porosity changes. However, as another method, it is known to change the adhesive contained in the ceramic green sheet, and to form the structure according to the present invention by using the method of the invention, that is, the porosity of the effective layer is as high as the conventional one, and the protective layer is When the porosity is lower than that of the effective layer, the ceramic precursor used in the semiconductor ceramic layer constituting the protective layer may be considered to be laminated, compared to the ceramic used in the semiconductor layer constituting the active layer. The film reduces the amount of polystyrene particles or the ceramic tablets. However, for example, if you want to change the amount of polystyrene particles to determine the size of the ceramic tablets, the polystyrene particles themselves are not helpful. As a result of stickiness, there is a lack of adhesion between the slabs of the ceramics. The amount of organic components such as =, and the accumulation of the slabs and the slabs of the slabs are burned in one place. Gas - On the other hand, the present invention can maintain the porosity of the effective layer at the same level as in the past, even if the amount of the polystyrene particles or the bonding amount of the polyphenylene oxide is not included in the semiconductor, and the protective layer is maintained. Porosity than the effective layer And the same as %, by forming the glazing film formed on the surface of the surface of the surface of the ceramic body by the second invention according to the present invention, at least the substrate is mounted, and the second can be surely prevented. : Infiltrating into the interior of the ceramic body by I3283.doc 200903527. 7 Moreover, by forming the structure of the third invention of the present invention, for example, when performing the energization test, the resistance before and after the energization test can be reduced. The inventors of the present invention have conducted a power-on test by soldering 'the laminated positive thermal resistor according to the above-mentioned Patent Document 1' and conducted an energization test, and it was found that the resistance value before and after the energization test was large. Since the flux is infiltrated from the portion of the ceramic body adjacent to the substrate, that is, from the surface of the ceramic body, particularly from the surface portion (LxW surface) on the side of the mounting surface. The reason is still unknown, but the glass film formed in the pores is formed with tiny cracks. When the laminated positive thermistor is mounted on the substrate, the stress is added between the ceramic body and the external electrode to be welded. The surface portion on the mounting surface side of the element body and the (four) length in the vicinity of the connection portion with the external electrode. If the energization test is carried out under (4), it is presumed that the refining agent fixed on the surface of the glass film will be reduced in viscosity with the heat of the ceramic body, and it is easy to invade the ceramics by the phenomenon of capillary phenomenon. Inside the body. According to the third invention of the present invention, by making the porosity of the protective layer 10% or less, the existence ratio of the pores of the protective layer can be reduced, and the formation of the glass (four) can be sufficiently performed in the further step, so that the fluxing agent can be further prevented. Infiltration. [Embodiment] Hereinafter, an embodiment of a laminated positive thermal resistor of the present invention will be described in detail based on the drawings. Fig. 1 is a schematic cross-sectional view showing an embodiment of a laminated positive thermal resistance device of the present invention. The laminated positive thermal resistor W of the present invention has a plurality of internal electrodes 3aa, 3ab 3ba and 3bb embedded therein with a semiconductor ceramic layer 129283.doc 200903527 2a~M body 4. Then, at both end portions of the ceramic body 4, the external electrode domains % are formed by electrically connecting the internal electrodes ^3ab, 3ba, and 3bb. That is, the internal electrodes 3aa, 3ab are alternately drawn on one end face of the ceramic body 4, and the internal electrodes are formed by alternately leading out the other end faces of the ceramic body 4. Then, the external electrode system is electrically connected to the internal electrodes 3aa to 3ab, and the external electrode 5b is electrically connected to the internal electrode. In the step of forming the first plating film 6a, 6b formed on the surface of the external electrode, the first plating film 6a, 6b is formed in the first plating layer, and the surface is formed to form a second plating layer formed by Sn or the like. 7a, 7b. In the semiconductor ceramic layer 2 of the present invention, the semiconductor ceramic layer (10) located between the two inner electrodes 3 - 3ab located at the outermost side in the lamination direction is regarded as the effective layer B 'is the most in the lamination direction The two inner electrodes 3ba and 3ab on the outer side are located on the surface of the ceramic surface of the ceramic body and the k is used as the protective layer A. The protective layer A and the effective lanthanum of the present invention contain the curry 3 as the main component. The cation radius of the conductor material contained in the protective layer A is larger than the ionization radius of the semiconductor compound containing the effective layer. The ionic radius of the present invention is used as The semi-conducting of the starting material, the ionic radius of the chemical (6-coordinate) is given as *. For example, as the active layer B, the material * is used for the main component of BaTi〇3, and Sm3 + (〇96A) is added as the V body. In the case of the chemical agent, as the protective layer of the eight ceramic materials, the main component of the ^ 3 is common ' May be used Ν · .98Α) and LU3A) as a semiconductor-forming agent and the like. Further 'radius of each ion according to the present invention based 129283.doc 200903527

Handbook of Chem. & Phys., 79th Edition, γ. q Jia j Solid State Chem,, 95 (1991) 184.

With this type of structure, the laminated positive thermal resistor of the present invention obtains a structure in which the porosity of the active layer B is maintained at an I state which is higher than that of the conventional phase, and the porosity of the protective layer A is low. As the class of the semiconductorizing agent, a rare earth element can be used, and La, Ce, Pr, Nd, Sm, Eu, (5), several, d" γ,

At least one of Ho, Er, and Tm is selected. Further, when a plurality of kinds of rare earth elements are added to each of the protective layer 8 and the effective layer B, the average of the addition ratio and the ionic radius of the semiconductorizing agent can be compared. Further, the porosity of the entire semiconductor ceramic layers 2a to 2e of the present invention is 10% or more and 35% or less. Further, the porosity of the present invention is a ratio (%) of pores of the semiconductor ceramic material which is not baked. By setting the porosity, the oxygen in the reoxidation treatment is spread over the center of the ceramic body 4, so that the laminated positive thermal resistor 1 having excellent resistance change rate can be obtained, and the semiconductor ceramic layers 2a to 2e are all present. When the porosity is more than 35%, the bulk strength of the ceramic body 4 may decrease, or the room temperature resistance value may become high. Further, when the porosity of the semiconductor ceramic layer 2 is less than ι〇%, since the reoxidation treatment does not proceed smoothly, a sufficient resistance change rate and a change in the room temperature resistance value with time are not obtained. The rate becomes larger. Further, regarding the protective layer A of the present invention, the porosity is preferably 1% or less. In the case of such a structure, a small change in resistance value before and after the energization test can be obtained. In addition, the ratio of the portion such as the Ba portion and the T1 portion of the BaTi〇3-based ceramic material which is the main component of the present invention (hereinafter referred to as the Ba portion/Ή portion) is preferably 0.998 or more and 129283.doc -13·200903527 1.006 or less. When the right Ba portion/Ti portion is smaller than 〇, the resistance change rate tends to be small. Further, when the Ba portion/Ti portion exceeds 1.006, the room temperature resistance value tends to become high, and the coefficient of increase in resistance becomes unstable. Further, the content of the semiconductorizing agent added to the protective layer A and the effective layer B of the present invention is Til〇〇mole of the BaTi〇3 ceramic material which is the main component of the protective layer A and the effective layer B, respectively. Department, it should be 〇"

Up, 〇.5 Moel below. When the content of the semiconductorizing agent is smaller than the U molar portion with respect to the TilOO molar portion, the semiconductorization of the BaTi〇3 ceramic material cannot be sufficiently performed. Further, when the content of the semiconductorizing agent is higher than the case where the (10) molar portion exceeds 0.5 mol, the room temperature resistance value tends to be high. The internal electrodes 3aa, 3ab, 3ba and 3bb of the present invention are preferably semiconductor ceramics. The material having excellent ohmic contact of the layers 2a to 2e is preferably a monomer or an alloy of a base metal material such as Ni or α. The internal electrode of the present invention uses a conductive metal material containing Ni, Cu or the like as a conductive component. Further, as the external electrodes 53 and 5b, a monomer and an alloy of a noble gold >1 material such as Ag, Ag-Pd, and Pd, or a monomer of a Ni and (10) soap metal material, and a gold or the like may be used. Further, it is preferable to connect and conduct the internal electrodes 3aa, 3ab, 3ba, and 3bb. Further, a glass film (not shown) is preferably formed in a portion corresponding to the protective layer A. Further, it is not necessary to All the pores existing in the protective layer 8 form a glass film, and at least the pores present on the surface side of the ceramic body are covered by the glass film. The pores of the protective layer 8 are covered by the glass crucible, even by welding. Substrate It is still possible to prevent the flux contained in the solder from infiltrating into the interior of the ceramic body. Moreover, the hole in the protective layer A I29283.doc 14 200903527 has a structure in which a glass film is formed, and the outer surface of the clothing surface is not formed. The portions of the electrodes 53 and 5b are "insulated by a glass layer or a resin layer, such as a μ D . Hunting forms such an insulating layer, into a shadow plastic, π #, / not easy to owe to the external environment ~ ring = can reduce the deterioration of characteristics caused by temperature, humidity and so on. Next, an embodiment of the coating & method of laminating positive 埶 ^ ^ ... 1 state 1 will be described using, for example, the use of a protective layer A...antifoaming agent as the effective abundance conductor. First, as the raw material for the protective layer A, BaC〇3, Ti〇2, and the amount of the second amount are used as the pottery raw materials for the effective layer B, and the specific amount of ^Tl〇2, Sm2〇3 is measured. 'The various quantities and parts of the stability of eight; Hummer PSZ ball) together into the ball mill, charge two: two wet ... crush 'after the specific temperature (for example, 1 ~ ~) into the calcined 'made a protective layer A ceramic powder ceramics powder. The double-layer β is used in the protective layer, and the organic binder is added to the ceramic powder by the ceramic powder of the ceramic powder, and the ceramic powder is added to the ceramic powder to form the σ treatment in a wet manner. Slurry. Thereafter, using the doctor blade method to calculate the Η 丄 , 丄 m ^ 4 sheet forming method, the protection obtained

The layer A was formed into a sheet by using a slurry and an effective layer B ❹ Δ田 & and the ceramic slab for the protective layer A and the ceramic slab for the effective layer B were produced. Next, it is prepared to use Ni as a main component, and to form a conductive paste for the N1 internal electrode of the knife. After that, on the ceramic green sheet of the effective layer B, the second fine is printed by screen printing or the like to print a conductive paste for the inner electrode of the Ni. Next, the Ni internal electrode is arranged to be alternately extracted from the opposite ends of the ceramic body after the baking of the conductive paste by the conductive paste, and the Ni is internally printed on the laminate side. 129283.doc -15 - 200903527 In the active layer B of the conductive paste, the protective layer A on which the conductive paste for the state internal electrode is not printed is used for the ceramic sheet, and a plurality of sheets are placed on the upper and lower sides to be pressed to produce uncooked Laminated. Next, the laminated body is cut into a material size, and is housed in a (four) lyrics (set), at a specific temperature (for example, fan ~ 400. 〇 after debonding treatment, under a reducing atmosphere (for example, 3% degree) ), at a specific temperature (for example, 丨1〇〇~13〇〇.〇), a sinter-fire treatment is performed to form an alternating layer of internal electrodes ~, and a ceramic body 4 with ceramic layers 2a to 2e. The oxidized body 4 obtained as described above is reoxidized at a specific temperature (for example, 5 〇〇 to 70 (TC)' in an atmospheric atmosphere or an oxygen atmosphere. Next, the obtained ceramic body 4 is obtained. Immersed in a glass solution containing, for example, a oxidized stone as a main component, and filling the glass component with each of the pores of the protective layer A located on the surface of the ceramic body. Further drying the body 4 to thereby protect the protective layer A Each of the pores forms a glass film. Then, at both ends of the Taman body 4, an external electrode mainly composed of Ag is formed by ruthenium plating. Further, on the surface of the external electrode, the electric field is used for electric field ore. Ni plating films 6a and 6b, Sn plating film and a few are formed to obtain laminated positive heat In addition, as a method of forming the external electrodes 53 and 5b, a conductive paste for external electrodes which is a main component is prepared, and is baked at a specific temperature (for example, 500 to 8') on both end faces of the ceramic body 4 The outer electrode region % may be formed as H. If the adhesion is good, another film forming method such as vacuum distillation may be used. Moreover, the heating of the external electrode conductive paste may also serve as a ceramic. The reoxidation treatment of the element body 4. Further, the present invention is not limited to the above embodiment. In the above embodiment, 129283.doc 200903527, an oxide is used as a semiconducting material, etc. A thousand v body ceramic material, but carbonic acid may also be used. Further, the salt-positive thermistor 1 of the present invention is useful for the use of the overcurrent protection, and is useful for the temperature detection, but is not limited thereto. 3, 3ab, 3ba, and 3bb are connected to the external electrodes 5a and 5b, but the internal electrodes (for example, 3aa, 3bb) of the parent group or more are connected to the connection via the semiconductor Taoshen θ2. Outside the different potentials The poles 5a, 5b can be used, and the inner electrodes (for example, 3ab, 3bb) do not have to interact to form a laminated positive thermal resistor that is not limited to the shape shown in Fig. 1. Specifically, the laminated positive resistance number of the present invention will be described. (Example 1) '' Β First, BaC〇3, Dings 2, γ2〇3 are prepared as starting materials.

Dy2〇3, sm2〇3, Nd2〇3, and La2〇3, the amount of the additive is as shown in the following formula. (Bao.mAo.^TiO3 (where A represents the rare earth element in the above starting materials) In addition, the ionic radius of the trivalent 6-coordinate of Y, Dy, Sm, Nd and La is 〇, 9〇 from the left. A, 0.91A, 〇.96A, 0.98A, 〇3A. Next, pure water is added to each of the starting materials of the seed amount, and pulverized by a ball mill and smashed for 1G hours, and dried to i(10). After calcination for 2 hours, it is pulverized together with the PSZ ball by a ball mill to obtain a calcined powder. Then, the obtained calcined powder is added with an organic acrylic acid agent, a dispersant and water, and a PSZ ball. The mixture was mixed for 15 days to obtain a ceramic slurry. 129283.doc 200903527 Then, the obtained ceramic material was formed into a sheet shape by a doctor blade method to be dried to obtain a thickness of 3 μM. Next, the metal powder and the organic binder are dispersed in an organic solvent to obtain a conductive paste for the internal electrode, and then prepared separately for the ceramic layer corresponding to the effective layer. On the main surface, the state-of-the-art electrode paste is screen-printed so that the thickness of the electrode after sintering becomes about Each of the H-embry internal electrodes printed with the electric (4) conductive paste is interspersed with a conductive paste. The ceramic is the embryo and the father is opposite to each other, and 25 pieces of Tao Jing's embryos are overlapped. Step-by-step}}Customer 1 1 JQ ^ Progress will be equivalent to the protective layer of the protective layer with ceramic tiles, 5 pieces arranged on the top and bottom, pressed, cut into L size 23 mmxW size 1.6 mmxT ruler, 1. The size of the inch is obtained by the size of the mm. In the atmosphere, 40 (Tr, 1 ο I. 士',,,,,,,,,,,,,,,,,,,,,,,,,, Divided into the calcination temperature shown in Table 1 for 2 hours to obtain (4) the layer of the (4) layer that interacts with the internal electrode. The receiver will receive the ceramics to read, and the main 'A' will be barrel-polished. The ceramic body, and / / in the UL] - S 〇 之 oxidation (10) for heat treatment, after ... into a glass solution of the knife, after the film, in the atmosphere of the gas in the pores of the protective layer to form glass ^, under the Gong, reoxidation treatment of 7 ° ° C. Thereafter, on both ends of the ceramic body, ore, thereby forming an external electrode. XCu Cmg order for the final off, the external electrodes in Table

The Sn electric bond sequentially performs electric ore film formation, and the positive electric resistance is obtained as the electric ore and the sound accumulated as obtained above. ..Έ. ^ ^ θ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 200903527 Configured on a oxidized substrate, put a smoked f i+* coin-baked tissue at 85 ° C, and apply a voltage of 24 V for 1000 hours. Then take it out from the seat & The same method was used before the substrate was mounted to measure the value of the electric power P of the thermal resistor after the energization test. Then, the rate of change of the room temperature and the 'resistance of the dish' before and after the energization test was calculated, and the samples were set to samples 1 to 25. The results are shown in Table 1. [Table 1]

*Before the scope of the present invention, it can be seen from Table 1 that the catalyst for the semiconductor layer contained in the protective layer is larger than the ionic radius of the semiconductor compound contained in the effective layer, and the samples have a large ionic radius of 2 to 5: 8 to 10, 14, 15 and 2〇, the porosity of the effective layer is maintained as high as the previous one, and the porosity of the protective layer becomes lower than the porosity of the effective layer = and it can be seen that the rate of change of the room temperature resistance value before and after the electrification test is as small as 5%. 129283.doc -19- 200903527 under. Further, regarding the samples 2 to 5, 8 to 1 〇, the porosity of the protective layer was below the wrist, ^14, 15 and 2G, and it was found that it was suitable because it was sufficiently glassy. Further, the ionic radius of the pore-shaped semiconductorizing agent in the protective layer can be regarded as the ion 7, 11 of the semi-conductive hybrid agent contained in the layer 67 of the sample having the same or smaller radius as the protective layer. 13,16 ~" ) c

It can be seen that the porosity of the protective layer is equal to or the same as the porosity of the effective layer. In the evaluation, it can be seen that the rate of change of the room temperature resistance value before and after the electrification test is two or that it is destroyed by the energization test and cannot be measured. for. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an embodiment of a laminated positive thermal resistor of the present invention. Approximate profile [Major component symbol description] 1 Laminated positive thermistors 2a to 2e Semiconductor ceramic layers 3aa to 3bb Internal electrodes 4 Ceramic bodies 5a, 5b External electrodes 6a, 6b Ni plating film 7a, 7b Sn plating film 129283.doc -20-

Claims (1)

200903527 Patent Application Range·· 1. A laminated positive thermal resistance device, comprising: a ceramic body, which is formed by a plurality of semiconductor ceramic layers and a plurality of inner layers, the semiconductor ceramic layers comprising BaTi〇 3 is a ceramic material containing a semiconductorizing agent, and the internal electrodes are formed along the interface of the front: abundance conductor ceramic layer; and the outer electrode of the phoenix is formed on both end faces of the ceramic body And the internal electrodes of the zebra said are electrically connected; 〃, the complex + conductor ceramic layer existing between the internal electrodes of the laminated layer &# L (4) is used as the effective layer, and the ratio is located at the outermost丨& Wan Xin, but the other side of the internal electrode is located in the ceramic pottery layer on the surface side of the ceramic body as the protective layer, the semiconductor ceramic ion radius of the protective layer, The ratio of the conductor to the ionic radius of the active layer is large. The semiconductorizer contained in the layer of ugly pottery 2. As requested! The laminated positive thermal resistor, the semiconductor ceramic layer, is formed in the "n-pore of the protective layer" at least in the pores of the above-mentioned ceramics, and the pores of the Qiu side are formed with a glass film. 3. For a laminated positive thermal resistor of π or 1 or 2, the ratio is 〖0% or less. The pore of the protective layer 129283.doc